Correct in terms of the manufacturer or the caliber?

Cases from the same mfg are more likely to be the same weight (see the "Does it make a difference" discussion above). 

Caliber is only useful as a pointer to what the round might fit, depending on whether or not you're making your .40-65 from .45-70.  The former will fire just fine in a .45-70 rifle (voice of experience here) but not will not be terribly accurate.

.32-40 made from .30-30 of limited interchangability so not a problem.